Acacia macnuttiana - vulnerable species listing

NSW Scientific Committee - final determination

The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list the shrub Acacia macnuttiana Maiden & Blakely as a VULNERABLE SPECIES in Part 1 of Schedule 2 of the Act, and as a consequence, to omit reference to Acacia macnuttiana Maiden & Blakely from Part 1 of Schedule 1 (Endangered species) of the Act. Listing of vulnerable species is provided for by Part 2 of the Act.

2. Acacia macnuttiana was originally described in 1927 from Bismuth, a mining area near Torrington in northern NSW. It is one of several closely related species in a complex of taxa ranging from central NSW to southern Queensland. One of these closely related species, Acacia acrionastes, has been recorded as occurring sympatrically with Acacia macnuttiana at Pindari Dam, south-east of Ashford (Kodela & Harden 2002). Acacia macnuttiana can be distinguished from Acacia acrionastes by its golden flower heads in groups of less than 10 per raceme (Acacia acrionastes typically has >10 creamy yellow heads per raceme).

3. Acacia macnuttiana is endemic to New South Wales where it is known from five broad localities: Bald Rock National Park, Boonoo Boonoo National Park, private property south-west of Tenterfield, the Torrington district, and along the banks of Pindari Dam. Additional records from Washpool National Parkand Severn River Nature Reserve are now believed to be erroneous.

4. Acacia macnuttiana grows in shallow, rocky soils derived from leucogranite acid volcanics. The vegetation ranges from heath on rocky outcrops to dry sclerophyll forest on deeper soils. Altitudes range from approximately 500 to 1100 m above sea level. Flowering is mostly from August to September with occasional late flushes in October. The fire response of Acacia macnuttiana is uncertain but the species is believed to most likely be an obligate seeder (Clarke & Fulloon 2000).

5. Acacia macnuttiana has been recorded from a number of conservation reserves such as Bald Rock National Park, Boonoo Boonoo National Park and Torrington State Conservation Area.

6. Acacia macnuttiana has a highly restricted geographic distribution. Its area of occupancy was estimated to be approximately 60 km2 based on 2 x 2 km grid squares, the spatial scale of assessment recommended by the IUCN (2008). All populations fall within an extent of occurrence of approximately 1220 km2 (Copeland 2008).

7. The total known population of Acacia macnuttiana has been estimated to include 500–1300 mature individuals (Copeland 2008). Approximately half of these occur in the Torrington district which has by far the largest population.

8. At present there appears to be no evidence that Acacia macnuttiana is undergoing a continuing decline. Most populations occur in protected areas that are subject to relatively few threats. Inappropriate fire regimes and grazing by feral goats could potentially threaten the species in the future.

9. Acacia macnuttiana is not eligible to be listed as a Critically Endangered species or as an Endangered species.

10. Acacia macnuttiana Maiden & Blakely is eligible to be listed as a Vulnerable Species as, in the opinion of the Scientific Committee, it is facing a high risk of extinction in New South Wales in the medium-term future as determined in accordance with the following criteria as prescribed by the Threatened Species Conservation Regulation 2002:

Clause 17

The total number of mature individuals of the species is observed, estimated or inferred to be:

(c) low.

Professor Lesley Hughes

Chairperson

Scientific Committee

Proposed Gazettal date: 19/12/08

Exhibition period: 19/12/08 - 27/02/09

References

Clarke PJ, Fulloon L (2000) Fire and Rare plants: Torrington State Recreation Area. (Unpublished report available from Botany, University of New England, Armidale)